Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!ames!husc6!uwvax!astroatc!glen
From: glen@astroatc.UUCP (Glen Ecklund)
Newsgroups: comp.lang.c
Subject: Re: swap macro
Message-ID: <787@astroatc.UUCP>
Date: 2 Feb 88 19:41:42 GMT
References: <8801200422.AA19420@decwrl.dec.com>
Reply-To: glen@astroatc.UUCP (Glen Ecklund)
Organization: Astronautics Technology Cntr, Madison, WI
Lines: 8
Summary: A new nit

> #define swap(a,b) ((a) = ((b) = ((a) = (a) ^ (b)) ^ (b)) ^ (a))
                                   <1>                       <2>

I'm surprised that nobody has picked the nit that drew my attention.
This macro requires the first assignment, at <1>, to be completed
before the last (a), at <2>, is evaluated.  My reading of K&R says
this cannot be assured.  Or did I miss something?

Glen Ecklund